I assume all vendors of such tools would be prepared to publish how fast
their software is at delivering data back to the calling application.
:)

Let me guess the answer ... "It depends".   

The fundamental point is .... that trying to use Cursors on a RDMBS will
never give you the performance you can get from native SQL approach.
Indeed most books on SQL, including M$soft SQL advise against this
approach. 

The example that was given to me was "raise everyone's base salary by 5%
" 

In native SQL this is a single line of SQL that executes in
milliseconds. 

In a legacy approach this is 

1: position at start of file
2: move to next record
3: update 
4: repeat 2 & 3 until end of file

This legacy approach is what most HP3000 applications do - they navigate
through the relevant files using DBGET or FREAD,  but because the
application and database are so close, then you get blistering
performance.  

The attempt to introduce a RDBMS at the back end introduces a layer of
software at both steps 2 and 3 - each has to be converted to a SQL call,
then executed on the target database (possibly hosted on another server)
and the resultant recordset or status codes returned back to the
application via the intermediate software.    

If you are prepared to accept this as the necessary evil of the
migration and are prepared to justify the higher costs and performance
problems to your management as a temporary problem when measured against
the long-term benefits 

For reference,  we tried exactly the above on both an cobol program
updating it's local database and a VB progarm updating a M$soft SQL
database.  The HP3000 won hands down. 



-----Original Message-----
From: Charles Finley [mailto:[log in to unmask]] 
Sent: 03 March 2006 14:08
To: Tony Summers; [log in to unmask]
Subject: RE: Migration recommendations; PRELIMINARY INQUIRY

Tony Summers Wrote:

"You can use cursors in SQL - and some 3rd party products have a proven
track record of translating image calls onto SQL calls on the target
database - but you would have to seriously consider the overhead of such
an approach."

While it is true that if you tried to run  the same application on HP
3000 hardware using a RDBMS with cursors, the performace would likely be
dismal, computers are commodity items today.  You can get high
performance computers that run UNIX, Linux and Windows that are very
inexpensive.  Our toolset, SunGard Bi-tech Transport is in use in
hundreds of installations with good performance.  Cursors are used
underneath.  Therefore, it has not been our experience that the above is
an issue.

Charles Finley
619-795-0720



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